Stihl MS 170 Chainsaw throwing the chain frequently

[Clint S]

They are a little lacking in power, but you get what you pay for as far as that. I have 2 and cut alot with them and maybe thrown a chain once even when running them a little ''loose'' trying to finish the last few cuts of the day . Small brush is tough and likes to ''catch '' the chain. Something is not right for it to do that.

 

[Coyote machine]

I had a small saw that throws chains especially when the chains are newish. It seems they stretch quite a bit and need to be tightened fairly often and don't let the chain sag.

Correct, chains will, when new, stretch. Everything needs to match, sprocket, bar, chain, and gauge of the chain to the bar, etc.
New chains will after some time stop stretching, but will still need to be adjusted, (tightened), or loosened if over-tightened by the user. Another thing that influences the chain/bar and saw in general is the oiler pathway. It includes the oil pump, tank, filter, bar rail(s) and so on. Without adequate oiling, the entire saw is at risk. The saw sprocket area needs to be cleaned and the oil holes in the bar need to be open and clean along with the bar's rails, so the oil can keep the chain from being damaged.

 

[CPTKILLER]

Thanks for the input.

 

[hslogger]

It aint the saw's falt. Chain or BAR. not "blade"
I would suggest you look those over and or replace.

I also suggest to those who have these small non pro saws that they change out the drive sprocket assembly. That means instead of using the "star" that is the drive for your chain, you change that assembly out for a star and rim, ie a free floating sprocket assembly. It floats and on the star, and the chain is driven by the rim. When you booger up your chains a lot, these will help you not to. One other thing, if you do switch to a rim assembly drive, chances are you will have to lengthen your chain a drive link or two.

 

[4570Man]

Among all my other saws I've a 021 which is about the same size. The only times I've thrown chains were when the chain was slightly loose and a twig caught between the chain and the blade. I've only sharpened a BLADE one or twice. Or did you mean chain?

I would also suggest a new chain and a standalone Stihl dealer. Often dealers that sell other "stuff" like toilet paper and bolts don't have the expertise for chainsaws.

I’ve never seen a stand alone Stihl dealer. As in a place that only sells Stihl products.

 

[CalG]

I have a Stihl MS 170 and use it for cutting brush around my small Central Texas Ranch near Gatesville, TX. It is a terrible chainsaw because it is unreliable. It throws a chain daily cutting brush usually 2" in diameter or less.

I had good success with Stihl products in Galveston County, Texas. As such I bought this small one based on that experience with chainsaws and weedeaters in a flood control district.

I took it back to Ace Hardware 2 or 3 times to get it worked on. Most recently, it has been throwing chains several times a day.

The mechanic reshapened the blade and verified that the chain tension was solid. He checked the blade also. I used it for two hours and then it threw a chain again.

Based on my experience, this is NOT A GOOD PRODUCT.

Any suggestions?

It's obviously a problem due to your location in TEXAS.

If you would send that saw here to me in Vermont, Don't bother with the bar or chain, they just add to the packing and shipping charges. I'll fit a new bar and chain at my end. I'm sure the saw and I could cut for hundreds of hours with only regular chain adjustments and adequate bar and chain oil.

 

[4570Man]

It's obviously a problem due to your location in TEXAS.

If you would send that saw here to me in Vermont, Don't bother with the bar or chain, they just add to the packing and shipping charges. I'll fit a new bar and chain at my end. I'm sure the saw and I could cut for hundreds of hours with only regular chain adjustments and adequate bar and chain oil.

At least he offered the location. I don’t think we could have ever got this figured out without it.

 

[Wagtail]

I’ve never seen a stand alone Stihl dealer. As in a place that only sells Stihl products.

Well then c'mon down here to St Helens... for a wee town we've got a STIHL shop. He also does small engine repairs.

 

[ArlyA]

Over the weekend, as we were clearing trail when my saw I had threw its chain. (I have many saws) I inspected everything and found nothing amiss, so I cleaned all components up* and reinstalled the chain. A while later the chain was thrown again. Upon closer inspection, I decided the bar had worn enough to cause this grief. We kept on sawing the rest of the day by keeping the chain a tad tighter than usual. We did have another saw head along but it and the truck was about 1 K away. (thats for our metric friends here

Thanks to all for the reminder...

* When we have the chain off for any reason, the bar/clutch cover, plus bar mounting plate is cleaned on the saw, and so is the bars grove as is the oil injection holes.

 

[CPTKILLER]

While I work on my chainsaw, I used my DeWalt Reciprocating Saw to trim brush. It worked and reminded me of an old Wright Reciprocating Saw except much lighter.

This is the load of brush that I cut with it this morning.

Next time I will use a different blade with a more coarse TPI.